Trough hoist apparatus and associated method

Abstract

A trough hoist apparatus that raises, dumps and lowers dough troughs includes a column assembly comprising a first column and a second column spaced laterally from the first column. A first externally threaded screw is mounted within the first column such that the first threaded screw extends vertically along a height of the first column. A second externally threaded screw is mounted within the second column such that the second threaded screw extends vertically along a height of the second column. A first drive assembly includes a first internally threaded drive nut internally receiving the first threaded screw. The first drive assembly is configured to rotate the first drive nut relative to the first threaded screw to move the first drive assembly vertically along the first threaded screw. A second drive assembly includes a second internally threaded drive nut internally receiving the second threaded screw. The second drive assembly is configured to rotate the second drive nut relative to the second threaded screw to move the second drive assembly vertically along the second threaded screw. A trough carriage assembly is located between the first column and the second column. The trough carriage assembly is mounted to the first drive assembly and the second drive assembly for vertical movement therewith. The trough carriage is configured to receive a dough trough.

1 . A trough hoist apparatus that raises, dumps and lowers dough troughs, the trough hoist apparatus comprising:
 a column assembly comprising a first column and a second column spaced laterally from the first column;   a first externally threaded screw mounted within the first column such that the first threaded screw extends vertically along a height of the first column;   a second externally threaded screw mounted within the second column such that the second threaded screw extends vertically along a height of the second column;   a first drive assembly including a first internally threaded drive nut internally receiving the first threaded screw, the first drive assembly configured to rotate the first drive nut relative to the first threaded screw to move the first drive assembly vertically along the first threaded screw;   a second drive assembly including a second internally threaded drive nut internally receiving the second threaded screw, the second drive assembly configured to rotate the second drive nut relative to the second threaded screw to move the second drive assembly vertically along the second threaded screw; and   a trough carriage assembly located between the first column and the second column, the trough carriage assembly mounted to the first drive assembly and the second drive assembly for vertical movement therewith, the trough carriage configured to receive a dough trough.   
     
     
         2 . The trough hoist apparatus of  claim 1 , wherein the first threaded screw is clamped at one end to the first column, the opposite end of the first threaded screw hanging free at a location above the bottom of the first column. 
     
     
         3 . The trough hoist apparatus of  claim 2 , wherein the second threaded screw is clamped at one end to the second column, the opposite end of the second threaded screw hanging free at a location above the bottom of the second column. 
     
     
         4 . The trough hoist apparatus of  claim 3 , wherein the first threaded screw and the second threaded screw are clamped at one end such that the first threaded screw and the second threaded screw do not rotate with their associated first drive nut and second drive nut. 
     
     
         5 . The trough hoist apparatus of  claim 1 , wherein the first drive assembly comprises
 a first motor including an output shaft;   a first driving gear connected to the output shaft of the first motor such that the first motor rotates the first driving gear;   a first driven gear operatively linked to the first driving gear for rotation therewith;   a first driven bushing connected to the first driven gear such that the first driven bushing rotates with the first driven gear, the first driven bushing including a bore through which the first threaded screw extends, the first driven bushing connected to the first driving nut such that the first driving nut rotates with the first driven bushing.   
     
     
         6 . The trough hoist apparatus of  claim 5 , wherein the second drive assembly comprises
 a second motor including an output shaft;   a second driving gear connected to the output shaft of the second motor such that the second motor rotates the second driving gear;   a second driven gear operatively linked to the second driving gear for rotation therewith;   a second driven bushing connected to the second driven gear such that the second driven bushing rotates with the second driven gear, the second driven bushing including a bore through which the second threaded screw extends, the second driven bushing connected to the second driving nut such that the second driving nut rotates with the second driven bushing.   
     
     
         7 . The trough hoist apparatus of  claim 5  further comprising a back-up nut located below the first driving nut and including an opening through which the first threaded screw extends, the back-up nut being linked to the first driving nut for rotation therewith such that in the event of excessive thread wear of the first driving nut, the back-up nut configured to support the first drive assembly during use. 
     
     
         8 . The trough hoist apparatus of  claim 7 , wherein, upon excessive thread wear of the first driving nut, the first driving nut disengages threads of the first threaded screw and drops vertically so that the back-up nut supports the first driving assembly thereon. 
     
     
         9 . The trough hoist apparatus of  claim 8  further comprising a detector arranged and configured to detect when the first driving nut drops vertically relative to the back-up nut. 
     
     
         10 . The trough hoist apparatus of  claim 1  further comprising first bellows having an opening extending therethrough through which the first threaded screw extends, the first bellows having a lower end connected to the first drive assembly so that the lower end moves with the first drive assembly. 
     
     
         11 . The trough hoist apparatus of  claim 1  further comprising a controller configured to synchronize movement of the first drive assembly and the second drive assembly. 
     
     
         12 . The trough hoist apparatus of  claim 1  further comprising an adjustment assembly configured to guide the first drive assembly within the channel of the first column. 
     
     
         13 . The trough hoist apparatus of  claim 1  further comprising
 a dough trough removably received and carried by the trough carriage assembly; and   a track associated with the at least one of the first column and the second column, the track having a component that causes tilting of the trough carriage assembly for a dumping operation.   
     
     
         14 . The trough hoist apparatus of  claim 11  further comprising one or more position transducers arranged and configured to detect the linear position of one or both of the first drive assembly and the second drive assembly. 
     
     
         15 . The trough hoist assembly of  claim 14 , wherein the position transducer is a string potentiometer. 
     
     
         16 . A method of moving dough using a trough hoist apparatus, the method comprising:
 placing a dough trough in a trough carriage assembly located between a first column and a second column of a column assembly comprising the first column and the second column spaced laterally from the first column;   driving a first drive assembly to which the trough carriage assembly is mounted, the first drive assembly including a first internally threaded drive nut internally receiving a first threaded screw mounted in the first column, the first drive assembly rotating the first drive nut relative to the first threaded screw thereby moving the first drive assembly vertically along the first threaded screw; and   driving a second drive assembly to which the trough carriage is mounted, the second drive assembly including a second internally threaded drive nut internally receiving a second threaded screw mounted in the second column, the second drive assembly rotating the second drive nut relative to the second threaded screw thereby moving the second drive assembly vertically along the second threaded screw.   
     
     
         17 . The method of  claim 16  further comprising clamping the first threaded screw at one end to the first column, the opposite end of the first threaded screw hanging free at a location above the bottom of the first column. 
     
     
         18 . The method of  claim 17  further comprising clamping the second threaded screw at one end to the second column, the opposite end of the second threaded screw hanging free at a location above the bottom of the second column. 
     
     
         19 . The method of  claim 16  further comprising
 driving a first driving nut using a first motor;   driving a first driven gear operatively linked to the first driving gear for rotation therewith; and   driving a first driven bushing connected to the first driven gear such that the first driven bushing rotates with the first driven gear, the first driven bushing including a bore through which the first threaded screw extends, the first driven bushing connected to the first driving nut such that the first driving nut rotates with the first driven bushing.   
     
     
         20 . The method of  claim 19  further comprising linking a back-up nut to the first driving nut, the back-up nut including an opening through which the first threaded screw extends, the back-up nut being linked to the first driving nut for rotation therewith such that in the event of excessive thread wear of the first driving nut, the back-up nut supporting the first drive assembly during use. 
     
     
         21 . The method of  claim 20 , wherein, upon excessive thread wear of the first driving nut, the first driving nut disengaging threads of the first threaded screw and dropping vertically so that the back-up nut supports the first driving assembly thereon. 
     
     
         22 . The method of  claim 21  further comprising detecting when the first driving nut drops vertically relative to the back-up nut using a detector. 
     
     
         23 . The method of  claim 22  further comprising the detector providing an excessive wear indication to a controller in response to the vertically dropping of the driving nut relative to the back-up nut, the controller lowering the first and second drive assemblies to their fully lowered position in response to the excessive wear indication.